Semiconductor device manufacturing method

ABSTRACT

A method includes a first process in which a first wiring is provided on a surface of a semiconductor substrate; a second process in which a light transmitting substrate is attached to the surface; a third process in which the semiconductor substrate is thinned so that the thickness of the semiconductor substrate is smaller than the thickness of the light transmitting substrate; a fourth process in which a through hole is formed in the semiconductor substrate; a fifth process in which a dip coating method is performed using a resin material and thus a resin insulating layer is provided; a sixth process in which a contact hole is formed in the resin insulating layer; and a seventh process in which a second wiring is provided on a surface of the resin insulating layer, and the first wiring and the second wiring are electrically connected via a contact hole.

TECHNICAL FIELD

The present invention relates to a method of manufacturing asemiconductor device.

BACKGROUND ART

In semiconductor devices such as an optical device and an electronicdevice, a front surface side and a rear surface side of thesemiconductor substrate are electrically connected to each other via athrough hole formed in the semiconductor substrate (for example, referto Patent Literature 1).

CITATION LIST Patent Literature

Patent Literature 1: Japanese Unexamined Patent Publication No.2004-57507

SUMMARY OF INVENTION Technical Problem

In the semiconductor device described above, the semiconductor substratetends to become thinner according to reduction in size thereof, highintegration, and the like. As a result, when the semiconductor device ismanufactured, damage is likely to occur in a peripheral portion of thethrough hole, and it is difficult to ensure electrical insulationbetween a wiring in the through hole and the semiconductor substrate.

Here, an object of the present invention is to provide a method ofmanufacturing a semiconductor device through which it is possible toprevent damage to a peripheral portion of a through hole while thinninga semiconductor substrate, and it is possible to ensure electricalinsulation between a wiring in the through hole and the semiconductorsubstrate.

Solution to Problem

According to one aspect of the present invention, there is provided amethod of manufacturing a semiconductor device, including a firstprocess in which a first wiring is provided on a first surface of asemiconductor substrate including the first surface and a second surfaceopposite to each other; a second process in which a support substrate isattached to the first surface after the first process; a third processin which a portion of the semiconductor substrate on the second surfaceside is removed and thus the semiconductor substrate is thinned so thatthe thickness of the semiconductor substrate is smaller than thethickness of the support substrate after the second process; a fourthprocess in which a through hole to extend from the first surface to thesecond surface is formed in the semiconductor substrate, and a part ofthe first wiring is exposed to a first opening of the through hole onthe first surface side after the third process; a fifth process in whicha dip coating method is performed using a first resin material and thusa resin insulating layer that is continuous through a second opening ofthe through hole on the second surface side is provided on an innersurface of the through hole and the second surface after the fourthprocess; a sixth process in which a contact hole is formed in the resininsulating layer, and the part of the first wiring is exposed to anopening of the contact hole on the first surface side after the fifthprocess; and a seventh process in which a second wiring is provided on asurface of the resin insulating layer, and the first wiring and thesecond wiring are electrically connected in the opening of the contacthole on the first surface side after the sixth process.

In the method of manufacturing a semiconductor device, processes afterthe process of thinning the semiconductor substrate are performed whilethe support substrate is attached to the semiconductor substrate.Accordingly, it is possible to prevent damage to a peripheral portion ofthe through hole. In addition, when the dip coating method is performed,the resin insulating layer is formed. Accordingly, it is possible toreliably form the resin insulating layer having a sufficient thicknessat which electrical insulation can be ensured. Therefore, according tothe method of manufacturing a semiconductor device, it is possible toprevent damage to the peripheral portion of the through hole whilethinning the semiconductor substrate, and it is possible to ensureelectrical insulation between a wiring in the through hole and thesemiconductor substrate.

In the method of manufacturing a semiconductor device according to oneaspect of the present invention, in the fifth process, the semiconductorsubstrate to which the support substrate is attached may be immersed inthe stored first resin material so that a liquid level of the storedfirst resin material intersects the first surface, and the semiconductorsubstrate to which the support substrate is attached may be pulled outof the stored first resin material so that the liquid level of thestored first resin material intersects the first surface. Accordingly,for example, compared to when immersion in and pulling out of the firstresin material are performed while the liquid level of the stored firstresin material and the first surface of the semiconductor substrate areparallel to each other, it is possible to reduce stress generated in theperipheral portion of the through hole. In addition, for example,compared to when immersion in and pulling out of the first resinmaterial are performed while the liquid level of the stored first resinmaterial and the first surface of the semiconductor substrate areparallel to each other, it is possible to prevent bubbles from remainingon the resin insulating layer formed on the inner surface of the throughhole.

In the method of manufacturing a semiconductor device according to oneaspect of the present invention, in the fifth process, the dip coatingmethod may be performed using the first resin material having aviscosity of 10 cp or more. Accordingly, it is possible to form theresin insulating layer having a sufficient thickness at which electricalinsulation can be ensured more reliably.

In the method of manufacturing a semiconductor device according to oneaspect of the present invention, in the sixth process, the first resinmaterial adhered to a surface of the support substrate on the sideopposite the semiconductor substrate in the fifth process may beremoved. Accordingly, for example, when the semiconductor device is anoptical device, even if a light transmitting substrate is used as thesupport substrate, since the first resin material is removed from thesupport substrate, the support substrate can effectively function as thelight transmitting substrate.

The method of manufacturing a semiconductor device according to oneaspect of the present invention may further include an eighth process inwhich a dip coating method is performed using a second resin materialand thus a resin protective layer is provided on a surface of the resininsulating layer to cover the second wiring after the seventh process,and a ninth process in which an opening is formed in the resinprotective layer and a part of the second wiring is exposed to theopening after the eighth process. Accordingly, it is possible toreliably form the resin protective layer having a sufficient thicknessat which the second wiring can be protected. In addition, a part of thesecond wiring can be used as a pad portion for electrical connectionwith the outside.

In the method of manufacturing a semiconductor device according to oneaspect of the present invention, in the eighth process, thesemiconductor substrate to which the support substrate is attached maybe immersed in the stored second resin material so that a liquid levelof the stored second resin material intersects the first surface, andthe semiconductor substrate to which the support substrate is attachedmay be pulled out of the stored second resin material so that the liquidlevel of the stored second resin material intersects the first surface.Accordingly, for example, compared to when immersion in and pulling outof the second resin material are performed while the liquid level of thestored second resin material and the first surface of the semiconductorsubstrate are parallel to each other, it is possible to reduce stressgenerated in a peripheral portion of the through hole. In addition, forexample, compared to when immersion in and pulling out of the secondresin material are performed while the liquid level of the stored secondresin material and the first surface of the semiconductor substrate areparallel to each other, it is possible to prevent bubbles from remainingon the resin protective layer formed on a region corresponding to thethrough hole.

In the method of manufacturing a semiconductor device according to oneaspect of the present invention, in the eighth process, the dip coatingmethod may be performed using the second resin material having aviscosity of 10 cp or more. Accordingly, it is possible to form theresin protective layer having a sufficient thickness at which the secondwiring can be protected more reliably.

In the method of manufacturing a semiconductor device according to oneaspect of the present invention, in the ninth process, the second resinmaterial adhered to a surface of the support substrate on the sideopposite the semiconductor substrate in the eighth process may beremoved. Accordingly, for example, when the semiconductor device is anoptical device, even if a light transmitting substrate is used as thesupport substrate, since the second resin material is removed from thesupport substrate, the support substrate can effectively function as thelight transmitting substrate.

In the method of manufacturing a semiconductor device according to oneaspect of the present invention, the first resin material and the secondresin material may be the same. Accordingly, even if the resininsulating layer and the resin protective layer are deformed due to achange in temperature, since the degrees of deformation are the same, itis possible to prevent damage to the second wiring caused by a largedifference between the degrees of deformation.

Advantageous Effects of Invention

According to the present invention, it is possible to provide a methodof manufacturing a semiconductor device through which it is possible toprevent damage to a peripheral portion of a through hole while thinninga semiconductor substrate, and it is possible to ensure electricalinsulation between a wiring in the through hole and the semiconductorsubstrate.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view of a semiconductor device according toan embodiment of the present invention.

FIG. 2 is a cross-sectional view of a through hole of the semiconductordevice in FIG. 1 and a peripheral portion thereof.

FIG. 3 is a plan view of a through hole of the semiconductor device inFIG. 1 and a peripheral portion thereof.

(a) and (b) of FIG. 4 are cross-sectional views for describing oneprocess in a method of manufacturing the semiconductor device in FIG. 1.

(a) and (b) of FIG. 5 are cross-sectional views for describing oneprocess in the method of manufacturing the semiconductor device in FIG.1.

(a) and (b) of FIG. 6 are cross-sectional views for describing oneprocess in the method of manufacturing the semiconductor device in FIG.1.

(a) and (b) of FIG. 7 are cross-sectional views for describing oneprocess in the method of manufacturing the semiconductor device in FIG.1.

(a) and (b) of FIG. 8 are cross-sectional views for describing oneprocess in the method of manufacturing the semiconductor device in FIG.1.

FIG. 9 is a cross-sectional view for describing one process in themethod of manufacturing the semiconductor device in FIG. 1.

FIG. 10 is a partial cross-sectional view of the semiconductor device inFIG. 1.

FIG. 11 is a partial cross-sectional view of a modified example of thesemiconductor device in FIG. 1.

FIG. 12 is a partial cross-sectional view of a modified example of thesemiconductor device in FIG. 1.

FIG. 13 is a plan view of a through hole of the semiconductor device inFIG. 12 and a peripheral portion thereof.

FIG. 14 is a cross-sectional view of a modified example of the throughhole of the semiconductor device in FIG. 1 and a peripheral portionthereof.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described below in detailwith reference to the drawings. Here, the same or corresponding portionsin the drawings are denoted with the same reference numerals andredundant descriptions thereof will be omitted.

As shown in FIG. 1, a semiconductor device 1 includes a semiconductorsubstrate 2 including a first surface 2 a and a second surface 2 b thatare opposite to each other. The semiconductor device 1 is an opticaldevice, for example, a silicon photodiode. In the semiconductor device1, in a predetermined region on the first surface 2 a side in thesemiconductor substrate 2 made of, for example, N-type silicon, a P-typeregion 2 c in which P-type impurities are selectively diffused isprovided. On the first surface 2 a of the semiconductor substrate 2, afirst wiring 3 made of, for example, aluminum, is provided with an oxidefilm 4 therebetween. In the oxide film 4, an opening 4 a is formed in aportion corresponding to a pad portion 3 a of the first wiring 3. Anopening 4 b is forming in a portion corresponding to an end of theP-type region 2 c in the oxide film 4. The first wiring 3 iselectrically connected to the P-type region 2 c through the opening 4 b.Here, instead of the oxide film 4, an insulating film made of anotherinsulating material such as SiN may be provided.

A light transmitting substrate 5 made of a light transmitting materialsuch as glass is arranged on the first surface 2 a of the semiconductorsubstrate 2. The semiconductor substrate 2 and the light transmittingsubstrate 5 are optically and physically connected by an adhesive layer6 including an optical adhesive. In the semiconductor device 1, lightenters the P-type region 2 c through the light transmitting substrate 5and the adhesive layer 6. Here, the thickness of the semiconductorsubstrate 2 is smaller (thinner) than the thickness of the lighttransmitting substrate 5. As an example, the thickness of thesemiconductor substrate 2 is about several tens of μm, and the thicknessof the light transmitting substrate 5 is about several hundreds of μm.

In the semiconductor substrate 2, a through hole 7 to extend from thefirst surface 2 a to the second surface 2 b is formed. A first opening 7a of the through hole 7 is positioned on the first surface 2 a of thesemiconductor substrate 2, and a second opening 7 b of the through hole7 is positioned on the second surface 2 b of the semiconductor substrate2. The first opening 7 a is continuous with the opening 4 a of the oxidefilm 4 and is covered with the pad portion 3 a of the first wiring 3. Aninner surface 7 c of the through hole 7 is a tapered surface thatenlarges from the first surface 2 a to the second surface 2 b. Forexample, the through hole 7 is formed in a truncated quadrangularpyramid shape that enlarges from the first surface 2 a to the secondsurface 2 b. Here, when viewed in a direction parallel to a center lineCL of the through hole 7, there is no need to match an edge of the firstopening 7 a of the through hole 7 and an edge of the opening 4 a of theoxide film 4. For example, the edge of the opening 4 a of the oxide film4 may be positioned further inside than the edge of the first opening 7a of the through hole 7.

The aspect ratio of the through hole 7 is 0.2 to 10. The aspect ratio isa value obtained by dividing the depth of the through hole 7 (thedistance between the first opening 7 a and the second opening 7 b) bythe width of the second opening 7 b (the distance between opposite sidesof the second opening 7 b when the second opening 7 b has a rectangularshape, and the diameter of the second opening 7 b when the secondopening 7 b has a circular shape). As an example, the depth of thethrough hole 7 is 30 μm, and the width of the second opening 7 b is 130pan. In this case, the aspect ratio is 0.23.

A resin insulating layer 10 is provided on the inner surface 7 c of thethrough hole 7 and the second surface 2 b of the semiconductor substrate2. The resin insulating layer 10 is continuous through the secondopening 7 b of the through hole 7. The resin insulating layer 10 reachesthe pad portion 3 a of the first wiring 3 through the opening 4 a of theoxide film 4 inside the through hole 7 and has an opening 10 a on thefirst surface 2 a side of the semiconductor substrate 2.

On a surface 10 b (a surface on the side opposite the inner surface 7 cof the through hole 7 and the second surface 2 b of the semiconductorsubstrate 2) of the resin insulating layer 10, a second wiring 8 madeof, for example, aluminum, is provided. The second wiring 8 iselectrically connected to the pad portion 3 a of the first wiring 3 inthe opening 10 a of the resin insulating layer 10. Further, on thesurface 10 b (a surface on the side opposite the second surface 2 b ofthe semiconductor substrate 2) of the resin insulating layer 10, a thirdwiring 22 made of, for example, aluminum, is provided. The third wiring22 is electrically connected to the second surface 2 b of thesemiconductor substrate 2 in an opening 10 c formed in the resininsulating layer 10.

The second wiring 8 and the third wiring 22 are covered with a resinprotective layer 21. A shallow recess 21 a having a smooth inner surfaceis formed in a portion corresponding to the through hole 7 in the resinprotective layer 21. An opening 21 b for exposing a pad portion 8 a isformed in a portion corresponding to the pad portion 8 a of the secondwiring 8 in the resin protective layer 21. An opening 21 c for exposingthe pad portion 22 a is formed in a portion corresponding to a padportion 22 a of the third wiring 22 in the resin protective layer 21. Inthe opening 21 b of the resin protective layer 21, an extractionelectrode 9 that is a bump electrode is arranged. The extractionelectrode 9 is electrically connected to the pad portion 8 a of thesecond wiring 8. In the opening 21 c of the resin protective layer 21,an extraction electrode 23 that is a bump electrode is arranged. Theextraction electrode 23 is electrically connected to the pad portion 22a of the third wiring 22. The semiconductor device 1 is mounted on acircuit substrate through the extraction electrode 9 and the extractionelectrode 23. The extraction electrode 9 and the extraction electrode 23function as an anode electrode and a cathode electrode, respectively.Here, instead of the resin protective layer 21, a protective layer (forexample, an oxide film and a nitride film) made of another insulatingmaterial may be provided. In addition, the thickness of the resinprotective layer 21 may be almost the same as the thickness of the resininsulating layer 10 or may be smaller than the thickness of the resininsulating layer 10. In particular, when the thickness of the resinprotective layer 21 is almost the same as the thickness of the resininsulating layer 10, it is possible to reduce stress applied to thesecond wiring 8 and the third wiring 22.

The resin insulating layer 10 described above will be described infurther detail with reference to FIG. 2. Here, in FIG. 2, the lighttransmitting substrate 5, the adhesive layer 6, and the resin protectivelayer 21 are not shown.

As shown in FIG. 2, the surface 10 b of the resin insulating layer 10has a first region 11 that reaches the first opening 7 a inside thethrough hole 7, a second region 12 that reaches the second opening 7 binside the through hole 7, and a, third region 13 that faces the secondsurface 2 b of the semiconductor substrate 2 outside the through hole 7.

The first region 11 is a tapered region that enlarges from the firstsurface 2 a to the second surface 2 b of the semiconductor substrate 2.The first region 11 has an average inclination angle α. When attentionis paid to a region on one side of the center line CL in the planeincluding the center line CL of the through hole 7, the averageinclination angle α of the first region 11 is an average value of anglesformed between an intersection line between the plane and the firstregion 11, and the first surface 2 a. When the intersection line is astraight line, an angle between the straight line and the first surface2 a is the average inclination angle α of the first region 11. When theintersection line is a curved line, an average value of angles betweenthe tangent of the curved line and the first surface 2 a is the averageinclination angle α of the first region 11. The average inclinationangle α of the first region 11 is greater than 0° and smaller than 90°.

The second region 12 is a tapered region that enlarges from the firstsurface 2 a to the second surface 2 b of the semiconductor substrate 2.The second region 12 has an average inclination angle β. When attentionis paid to a region on one side of the center line CL in the planeincluding the center line CL of the through hole 7, the averageinclination angle β of the second region 12 is an average value ofangles between an intersection line between the plane and the secondregion 12, and the first surface 2 a. When the intersection line is astraight line, an angle between the straight line and the first surface2 a is the average inclination angle β of the second region 12. When theintersection line is a curved line, an average value of angles betweenthe tangent of the curved line and the first surface 2 a is the averageinclination angle β of the second region 12. The average inclinationangle β of the second region 12 is greater than 0° and smaller than 90°.

The average inclination angle β of the second region 12 is smaller thanthe average inclination angle α of the first region 11. That is, thesecond region 12 is a region having a gentler inclination than the firstregion 11. In addition, the average inclination angle β of the secondregion 12 is smaller than an average inclination angle γ of the innersurface 7 c of the through hole 7. That is, the second region 12 is aregion having a gentler inclination than the inner surface 7 c of thethrough hole 7. In the present embodiment, the average inclination angleα of the first region 11 is closer to the average inclination angle γ ofthe inner surface 7 c of the through hole 7 than the average inclinationangle β of the second region 12. Here, the relationship of the averageinclination angle α of the first region 11>the average inclination angleγ of the inner surface 7 c of the through hole 7>the average inclinationangle β of the second region 12 is established. When attention is paidto a region on one side of the center line CL in the plane including thecenter line CL of the through hole 7, the average inclination angle γ ofthe inner surface 7 c of the through hole 7 is an average value ofangles between an intersection line between the plane and the innersurface 7 c, and the first surface 2 a. When the intersection line is astraight line, an angle between the straight line and the first surface2 a is the average inclination angle γ of the inner surface 7 c of thethrough hole 7. When the intersection line is a curved line, an averagevalue of angles between the tangent of the curved line and the firstsurface 2 a is the average inclination angle γ of the inner surface 7 cof the through hole 7.

The surface 10 b of the resin insulating layer 10 further has a fourthregion 14 having a maximum convex curvature toward the side opposite theinner surface 7 c of the through hole 7 and a fifth region 15 along anedge of the second opening 7 b of the through hole 7. When attention ispaid to a region on one side of the center line CL in the planeincluding the center line CL of the through hole 7, the maximum convexcurvature toward the side opposite the inner surface 7 c of the throughhole 7 is a maximum curvature value of a portion that is curved in aconvex shape toward the side opposite the inner surface 7 c of thethrough hole 7 along the intersection line between the plane and thesurface 10 b. Here, the first region 11 is a region on the first opening7 a side of the through hole 7 (the first opening 7 a side in adirection parallel to the center line CL of the through hole 7) relativeto the fourth region 14 within the surface 10 b of the resin insulatinglayer 10 provided on the inner surface 7 c of the through hole 7. Thesecond region 12 is a region on the second opening 7 b side of thethrough hole 7 (the second opening 7 b side in a direction parallel tothe center line CL of the through hole 7) relative to the fourth region14 within the surface 10 b of the resin insulating layer 10 provided onthe inner surface 7 c of the through hole 7 (that is, a region betweenthe fourth region 14 and the fifth region 15).

The fourth region 14 is curved to continuously connect the first region11 and the second region 12. That is, the fourth region 14 is a roundedcurved surface and smoothly connects the first region 11 and the secondregion 12. Here, if it is assumed that the fourth region 14 is notprovided, when the first region 11 is extended to the second surface 2 bside of the semiconductor substrate 2, and the second region 12 isextended to the first surface 2 a side of the semiconductor substrate 2,an intersection line (a corner or an angulated portion) is formed by thefirst region 11 and the second region 12. The fourth region 14corresponds to a curved surface formed when the intersection line (acorner or an angulated portion) is round-chamfered. When attention ispaid to a region on one side of the center line CL in the planeincluding the center line CL of the through hole 7, the fourth region 14is a portion that is curved in a convex shape toward the side oppositethe inner surface 7 c of the through hole 7 between a portioncorresponding to the first region 11 and a portion corresponding to thesecond region 12 along the intersection line between the plane and thesurface 10 b.

The fifth region 15 is curved to continuously connect the second region12 and the third region 13. That is, the fifth region 15 is a roundedcurved surface and smoothly connects the second region 12 and the thirdregion 13. Here, if it is assumed that the fifth region 15 is notprovided, when the second region 12 is extended to the second surface 2b side of the semiconductor substrate 2 and the third region 13 isextended to the center line CL of the through hole 7, an intersectionline (such as a corner or an angulated portion) is formed by the secondregion 12 and the third region 13. The fifth region 15 corresponds to acurved surface formed when the intersection line (such as a corner or anangulated portion) is round-chamfered. When attention is paid to aregion on one side of the center line CL in the plane including thecenter line CL of the through hole 7, the fifth region 15 is a portionthat is curved in a convex shape toward the side opposite the edge ofthe second opening 7 b of the through hole 7 between the portioncorresponding to the second region 12 and a portion corresponding to thethird region 13 along the intersection line between the plane and thesurface 1013.

In the present embodiment, the first region 11, the fourth region 14,and the fifth region 15 are curved surfaces that are curved in a convexshape toward the side opposite the inner surface 7 c of the through hole7. The second region 12 is a curved surface that is curved in a convexshape toward the inner surface 7 c side of the through hole 7 (that is,a curved surface that is curved in a concave shape when viewed from theside opposite the inner surface 7 c of the through hole 7). The thirdregion 13 is a plane substantially parallel to the second surface 2 b ofthe semiconductor substrate 2. As described above, the fourth region 14is curved to continuously connect the first region 11 and the secondregion 12, and the fifth region 15 is curved to continuously connect thesecond region 12 and the third region 13. Therefore, the surface 10 b ofthe resin insulating layer 10 is a continuous surface (a surface inwhich there is no discontinuous portion such as an intersection line(such as a corner or an angulated portion) between a surface and asurface, and the regions 11, 12, 13, 14, and 15 are smoothly connected).

An average thickness of the resin insulating layer 10 provided on theinner surface 7 c of the through hole 7 is greater than an averagethickness of the resin insulating layer 10 provided on the secondsurface 2 b of the semiconductor substrate 2. The average thickness ofthe resin insulating layer 10 provided on the inner surface 7 c of thethrough hole 7 is an average value of the thickness of the resininsulating layer 10 in a direction perpendicular to the inner surface 7c. The average thickness of the resin insulating layer 10 provided onthe second surface 2 b of the semiconductor substrate 2 is an averagevalue of the thickness of the resin insulating layer 10 in a directionperpendicular to the second surface 2 b.

In a direction parallel to the first surface 2 a and the second surface2 b of the semiconductor substrate 2, an average thickness of theportion corresponding to the first region 11 within the resin insulatinglayer 10 is greater than an average thickness of the portioncorresponding to the second region 12 within the resin insulating layer10. In a direction parallel to the first surface 2 a and the secondsurface 2 b of the semiconductor substrate 2, an average thickness ofthe portion corresponding to the first region 11 within the resininsulating layer 10 is an average value of a distance between the firstregion 11 and the inner surface 7 c of the through hole 7 in thatdirection. In a direction parallel to the first surface 2 a and thesecond surface 2 b of the semiconductor substrate 2, an averagethickness of the portion corresponding to the second region 12 withinthe resin insulating layer 10 is an average value of a distance betweenthe second region 12 and the inner surface 7 c of the through hole 7 inthat direction.

In the resin insulating layer 10, the first region 11 is a surface of aportion having a height H from the first surface 2 a of thesemiconductor substrate 2 within the resin insulating layer 10 providedon the inner surface 7 c of the through hole 7. The height H is 112 of asum D of the thickness of the semiconductor substrate 2 (that is, adistance between the first surface 2 a and the second surface 2 b) andthe average thickness of the resin insulating layer 10 provided on thesecond surface 2 b of the semiconductor substrate 2 or less.

In the resin insulating layer 10, when a surface S passing through anedge of the opening 10 a of the resin insulating layer 10 and the edgeof the second opening 7 b of the through hole 7 is set as a boundarysurface, and a portion P1 on the inner surface 7 c side of the throughhole 7 with respect to the surface S and a portion P2 on the sideopposite the inner surface 7 c of the through hole 7 with respect to thesurface S are focused on, the volume of the portion P1 is larger thanthe volume of the portion P2. In addition, in the resin insulating layer10, when attention is paid to a region on one side of the center line CLin the plane including the center line CL of the through hole 7, an areaof a triangle T1 is larger than an area of a triangle T2. The triangleT1 is a triangle with vertices at the edge of the first opening 7 a ofthe through hole 7, the edge of the second opening 7 b of the throughhole 7, and the edge of the opening 10 a of the resin insulating layer10 on a plane including the center line CL of the through hole 7 (thatis, in the cross section in FIG. 2). The triangle T2 is a triangle withvertices at the edge of the opening 10 a of the resin insulating layer10, the edge of the second opening 7 b of the through hole 7, and thetop of the fourth region 14 on a plane including the center line CL ofthe through hole 7 (that is, in the cross section in FIG. 2).

The resin insulating layer 10 has a first curved portion 101, a secondcurved portion 102, and a third curved portion 103. The first curvedportion 101 covers the inner surface 7 c of the through hole 7 betweenthe first opening 7 a and the second opening 7 b. The second curvedportion 102 covers the edge of the second opening 7 b of the throughhole 7 (that is, an intersection line between the second surface 2 b ofthe semiconductor substrate 2 and the inner surface 7 c of the throughhole). The second curved portion 102 is formed to cross the secondsurface 2 b of the semiconductor substrate 2 and the inner surface 7 cof the through hole. In the present embodiment, regardless of whetherthe shape of the edge of the second opening 7 b is a rectangle or acircle, the edge of the second opening 7 b is not chamfered but has acorner (edge). The second curved portion 102 covers the corner. Thethird curved portion 103 covers the inner surface 7 c of the throughhole 7 between the first curved portion 101 and the second curvedportion 102. The first curved portion 101 and the third curved portion103 are separated from each other. The second curved portion 102 and thethird curved portion 103 are separated from each other. The surface 10 bof the resin insulating layer 10 (corresponds to the fourth region 14 inthe present embodiment) in the first curved portion 101 is curved in aconvex shape toward the side opposite the inner surface 7 c of thethrough hole 7. The surface 10 b of the resin insulating layer 10(corresponds to the fifth region 15 in the present embodiment) in thesecond curved portion 102 is curved in a convex shape toward the sideopposite the inner surface 7 c of the through hole 7. The surface 10 bof the resin insulating layer 10 (corresponds to the second region 12 inthe present embodiment) in the third curved portion 103 is curved in aconvex shape toward the inner surface 7 c side of the through hole 7(that is, curved in a concave shape when viewed from the side oppositethe inner surface 7 c of the through hole 7). The curvature of thesurface 10 b of the resin insulating layer 10 in the first curvedportion 101 and the curvature of the surface 10 b of the resininsulating layer 10 in the second curved portion 102 are different fromeach other.

When attention is paid to a region on one side of the center line CL inthe plane including the center line CL of the through hole 7, a convexcurve to the side opposite the inner surface 7 c of the through hole 7means that an intersection line between the plane and the surface 10 bis curved in a convex shape toward the side opposite the inner surface 7c of the through hole 7. When attention is paid to a region on one sideof the center line CL in the plane including the center line CL of thethrough hole 7, a convex curve to the inner surface 7 c side of thethrough hole 7 means that an intersection line between the plane and thesurface 10 b is curved in a convex shape toward the inner surface 7 cside of the through hole 7.

As shown in FIG. 3, when viewed in a direction parallel to the centerline CL of the through hole 7, an outer edge of the second wiring 8 ispositioned outside the second opening 7 b of the through hole 7. Thatis, the outer edge of the second wiring 8 is positioned on a surface onthe side opposite the second surface 2 b of the semiconductor substrate2 within the surface 10 b of the resin insulating layer 10. Here, inFIG. 3, the resin insulating layer 10 is indicated by a dashed line, andthe second wiring 8 is indicated by an alternate long and two shortdashes line.

When the through hole 7 is formed in a truncated quadrangular pyramidshape that enlarges from the first surface 2 a to the second surface 2b, on the surface 10 b of the resin insulating layer 10 (corresponds tothe fifth region 15 in the present embodiment) in the second curvedportion 102, when viewed in a direction parallel to the center line CLof the through hole 7, a distance from each corner of the second opening7 b of the through hole 7 to the surface 10 b is greater than a distancefrom each side of the second opening 7 b of the through hole 7 to thesurface 10 b. Accordingly, at each corner of the second opening 7 b ofthe through hole 7, since the second curved portion 102 becomes agentler curved surface, it is possible to reliably prevent the edge ofthe second opening 7 b of the through hole 7 from being exposed, and itis possible to prevent a current from leaking between the second wiring8 and the semiconductor substrate 2 more reliably.

In addition, on the surface 10 b of the resin insulating layer 10(corresponds to the fourth region 14 in the present embodiment) in thefirst curved portion 101, when viewed in a direction parallel to thecenter line CL of the through hole 7, a distance from each corner of thefirst opening 7 a of the through hole 7 to the surface 10 b is greaterthan a distance from each side of the first opening 7 a of the throughhole 7 to the surface 10 b. Further, when viewed in a direction parallelto the center line CL of the through hole 7, regarding a distancebetween the surface 10 b of the resin insulating layer 10 (correspondsto the fifth region 15 in the present embodiment) in the second curvedportion 102 and the surface 10 b of the resin insulating layer 10(corresponds to the fifth region 15 in the present embodiment) in thesecond curved portion 102, the distance at each corner of the firstopening 7 a of the through hole 7 is greater than the distance at eachside of the first opening 7 a of the through hole 7. Accordingly, whilea corner (valley) of the through hole 7 having a truncated quadrangularpyramid shape is a portion in which an insulating film easily becomesthinner, it is possible to ensure a sufficient thickness of the resininsulating layer 10 at the corner (valley).

As described above, in the semiconductor device 1, the resin insulatinglayer 10 has the second curved portion 102 that covers the edge of thesecond opening 7 b of the through hole 7, and the surface 10 b in thesecond curved portion 102 is curved in a convex shape toward the sideopposite the inner surface 7 c of the through hole 7. Accordingly, thesurface 10 b of the resin insulating layer 10 provided on the innersurface 7 c of the through hole 7 and the surface 10 b of the resininsulating layer 10 provided on the second surface 2 b of thesemiconductor substrate 2 are smoothly connected. Therefore, duringmanufacture and after manufacture, a disconnection of the second wiring8 in a portion of the second opening 7 b of the through hole 7 isprevented. In addition, the resin insulating layer 10 has the firstcurved portion 101 that covers the inner surface 7 c of the through hole7 between the first opening 7 a and the second opening 7 b. The surface10 b in the first curved portion 101 is curved in a convex shape towardthe side opposite the inner surface 7 c of the through hole 7.Accordingly, for example, even if the diameter of the through hole 7 isreduced, a sufficient area of the opening 10 a of the resin insulatinglayer 10 on the first surface 2 a side of the semiconductor substrate 2is ensured. Therefore, during manufacture and after manufacture, adisconnection between the first wiring 3 and the second wiring 8 in aportion of the opening 10 a of the resin insulating layer 10 isprevented. Thus, according to the semiconductor device 1, a reliableelectrical connection via the through hole 7 in the semiconductorsubstrate 2 can be formed.

In the semiconductor device 1, the resin insulating layer 10 further hasthe third curved portion 103 that covers the inner surface 7 c of thethrough hole 7 between the first curved portion 101 and the secondcurved portion 102, and the surface 10 b in the third curved portion 103is curved in a convex shape toward the inner surface 7 c side of thethrough hole 7. Accordingly, for example, even if some external force isapplied to the first opening 7 a side from the second opening 7 b sideof the through hole 7, the third curved portion 103 functions as abuffer region. Therefore, it is possible to reduce stress generated in aportion connecting the first wiring 3 and the second wiring 8, and it ispossible to prevent a disconnection between the first wiring 3 and thesecond wiring 8 more reliably.

In the semiconductor device 1, the average thickness of the resininsulating layer 10 provided on the inner surface 7 c of the throughhole 7 is greater than the average thickness of the resin insulatinglayer 10 provided on the second surface 2 b. Accordingly, for example,even if the semiconductor substrate 2 is thinned, since the resininsulating layer 10 provided on the inner surface 7 c of the throughhole 7 functions as a reinforcing layer, it is possible to ensuresufficient strength of a peripheral portion of the through hole 7. Inaddition, it is possible to set an average inclination angle of thefirst region 11 and an average inclination angle of the second region 12to a desired angle, and it is possible to obtain the resin insulatinglayer 10 in which the surface 10 b is a continuous surface (a surface inwhich there is no discontinuous portion such as an intersection line(such as a corner or an angulated portion) between a surface and asurface, and the regions 11, 12, 13, 14, and 15 are smoothly connected).For example, when the resin insulating layer 10 is formed with a uniformthickness along the inner surface 7 c of the through hole 7, it is notpossible to obtain the resin insulating layer 10 in which the surface 10b is a continuous surface.

In the semiconductor device 1, the inner surface 7 c of the through hole7 is a tapered surface that enlarges from the first surface 2 a to thesecond surface 2 b. In this case, a reliable electrical connection viathe through hole 7 in the semiconductor substrate 2 can be formed.

In the semiconductor device 1, the first region 11 that reaches thefirst opening 7 a of the through hole 7 and the second region 12 thatreaches the second opening 7 b of the through hole 7 within the surface10 b of the resin insulating layer 10 are tapered regions that enlargesfrom the first surface 2 a to the second surface 2 b of thesemiconductor substrate 2. Thus, the average inclination angle of thesecond region 12 is smaller than an average inclination angle of theinner surface 7 c of the through hole 7. Accordingly, an angle betweenthe third region 13 that faces the second surface 2 b of thesemiconductor substrate 2 and the second region 12 that reaches thesecond opening 7 b of the through hole 7 within the surface 10 b of theresin insulating layer 10 is greater (that is, gentler) than an anglebetween the second surface 2 b of the semiconductor substrate 2 and theinner surface 7 c of the through hole 7. Therefore, during manufactureand after manufacture, a disconnection of the second wiring 8 in aportion of the second opening 7 b of the through hole 7 is prevented. Inaddition, for example, compared to when the resin insulating layer 10 isformed with a uniform thickness along the inner surface 7 c of thethrough hole 7, since the inclination of the second region 12 becomesgentler, it is possible to form the second wiring 8 easily and reliably.Further, since it is possible to form the second wiring 8 withoutdepending on the shape of the inner surface 7 c of the through hole 7,for example, even if a pointed portion remains on the inner surface 7 cof the through hole 7, it is possible to prevent a disconnection of thesecond wiring 8 caused by such a portion. In addition, the averageinclination angle of the second region 12 is smaller than the averageinclination angle of the first region 11. In other words, the averageinclination angle of the first region 11 that reaches the first opening7 a of the through hole 7 is greater than the average inclination angleof the second region 12. Accordingly, for example, even if the diameterof the through hole 7 is reduced, a sufficient area of the opening 10 aof the resin insulating layer 10 on the first surface 2 a side of thesemiconductor substrate 2 is ensured. Therefore, during manufacture andafter manufacture, a disconnection between the first wiring 3 and thesecond wiring 8 in a portion of the opening 10 a of the resin insulatinglayer 10 is prevented. Further, on the surface 10 b of the resininsulating layer 10, the fourth region 14 is curved to continuouslyconnect the first region 11 and the second region 12, and the fifthregion 15 is curved to continuously connect the second region 12 and thethird region 13. Therefore, during manufacture and after manufacture, adisconnection of the second wiring 8 is prevented in the entire regionof the surface 10 b of the resin insulating layer 10. In particular,after manufacture, since the stress concentration in the entire regionof the surface 10 b of the resin insulating layer 10 is reduced, this iseffective in preventing a disconnection of the second wiring 8. Asdescribed above, according to the semiconductor device 1, a reliableelectrical connection via the through hole 7 in the semiconductorsubstrate 2 can be formed.

In the semiconductor device 1, the surface 10 b of the resin insulatinglayer 10 is a continuous surface (a surface in which there is nodiscontinuous portion such as an intersection line (such as a corner oran angulated portion) between a surface and a surface, and the regions11, 12, 13, 14, and 15 are smoothly connected). Accordingly, the stressconcentration is reduced so that a disconnection of the second wiring 8can be prevented.

In the semiconductor device 1, the average inclination angle of thefirst region 11 is closer to the average inclination angle of the innersurface 7 c of the through hole 7 than the average inclination angle ofthe second region 12. Accordingly, it is possible to obtain the opening10 a having a sufficient area for exposing the pad portion 3 a of thefirst wiring 3. As a result, during manufacture and after manufacture,it is possible to prevent a disconnection between the first wiring 3 andthe second wiring 8 in a portion of the opening 10 a of the resininsulating layer 10 more reliably.

In the semiconductor device 1, the relationship of the averageinclination angle α of the first region 11>the average inclination angleγ of the inner surface 7 c of the through hole 7>the average inclinationangle β of the second region 12 is established. Accordingly, it ispossible to prevent a disconnection of the second wiring 8 and it ispossible to obtain the opening 10 a having a sufficient area forexposing the pad portion 3 a of the first wiring 3.

In the semiconductor device 1, in a direction parallel to the firstsurface 2 a and the second surface 2 b of the semiconductor substrate 2,an average thickness of the portion corresponding to the first region 11within the resin insulating layer 10 is greater than an averagethickness of the portion corresponding to the second region 12 withinthe resin insulating layer 10. Accordingly, it is possible to obtain theresin insulating layer 10 having a shape in which a disconnection of thesecond wiring 8 does not easily occur and a disconnection between thefirst wiring 3 and the second wiring 8 does not easily occur.

In the semiconductor device 1, for example, even if an overhang or thelike remains on the edge of the second opening 7 b of the through hole7, the overhang or the like is covered with the resin insulating layer10, and the second wiring 8 is provided on the fifth region 15 that is acurved surface curved in a convex shape. Accordingly, it is possible toreliably prevent a disconnection of the second wiring 8 in a portion ofthe second opening 7 b of the through hole 7.

In the semiconductor device 1, within the resin insulating layer 10provided on the inner surface 7 c of the through hole 7, a surface of aportion having a height H that is ½ of a sum D of the thickness of thesemiconductor substrate 2 and the average thickness of the resininsulating layer 10 provided on the second surface 2 b or less is thefirst region 11. Accordingly, on the surface 10 b of the resininsulating layer 10, the first region 11 and the second region 12 aresmoothly connected, and it is possible to reliably prevent adisconnection of the second wiring 8 at a boundary between the firstregion 11 and the second region 12.

In the resin insulating layer 10 of the semiconductor device 1, when thesurface S passing through the edge of the opening 10 a of the resininsulating layer 10 and the edge of the second opening 7 b of thethrough hole 7 is set as a boundary surface, and the portion P1 on theinner surface 7 c side of the through hole 7 with respect to the surfaceS and the portion P2 on the side opposite the inner surface 7 c of thethrough hole 7 with respect to the surface S are focused on, the volumeof the portion P1 is larger than the volume of the portion P2. Inaddition, when attention is paid to a region on one side of the centerline CL in the plane including the center line CL of the through hole 7,the area of the triangle T1 is larger than the area of the triangle T2.Accordingly, on the surface 10 b of the resin insulating layer 10, thefirst region 11 and the second region 12 are smoothly connected, and itis possible to reliably prevent a disconnection of the second wiring 8at a boundary between the first region 11 and the second region 12.

In the semiconductor device 1, within the surface 10 b of the resininsulating layer 10 provided on the inner surface 7 c of the throughhole 7, a region on the first opening 7 a side relative to the fourthregion 14 having the maximum convex curvature toward the side oppositethe inner surface 7 c of the through hole 7 is the first region 11, anda region on the second opening 7 b side relative to the fourth region 14is the second region 12. Such a shape of the resin insulating layer 10is particularly effective for forming a reliable electrical connectionvia the through hole 7 in the semiconductor substrate 2.

Next, a method of manufacturing the semiconductor device 1 describedabove will be described with reference to FIG. 4 to FIG. 9. First, asshown in (a) of FIG. 4, the P-type region 2 c is formed in thesemiconductor substrate 2, and the oxide film 4 and the first wiring 3are provided on the first surface 2 a of the semiconductor substrate 2(first process). Subsequently, as shown in (b) of FIG. 4, the lighttransmitting substrate (support substrate) 5 is attached to the firstsurface 2 a of the semiconductor substrate 2 with the adhesive layer 6therebetween (second process).

Subsequently, as shown in (a) of FIG. 5, when the second surface 2 b ofthe semiconductor substrate 2 to which the light transmitting substrate5 is attached is polished (that is, when a portion on the second surface2 b side of the semiconductor substrate 2 is removed), the semiconductorsubstrate 2 is thinned so that the thickness of the semiconductorsubstrate 2 is smaller than the thickness of the light transmittingsubstrate 5 (third process). In this manner, when the semiconductorsubstrate 2 is thinned, it is possible to easily form the through hole 7in a process subsequent thereto. In addition, it is possible to increasea response speed in the completed semiconductor device 1. Subsequently,as shown in (b) of FIG. 5, the through hole 7 is formed in thesemiconductor substrate 2 by anisotropic wet etching. Further, as shownin (a) of FIG. 6, a portion corresponding to the pad portion 3 a of thefirst wiring 3 in the oxide film 4 is removed, and the opening 4 a isformed in the oxide film 4. Accordingly, the pad portion 3 a of thefirst wiring 3 is exposed to the first opening 7 a of the through hole 7(fourth process). Here, when viewed in a direction parallel to thecenter line CL of the through hole 7, there is no need to form theopening 4 a in the oxide film 4 to match the edge of the first opening 7a of the through hole 7, and, for example, the opening 4 a may be formedin the oxide film 4 so that the edge of the opening 4 a of the oxidefilm 4 is positioned further inside than the edge of the first opening 7a of the through hole 7.

Subsequently, when a positive type first resin material having aviscosity of 10 cp or more is prepared and a dip coating method (amethod of immersing an object in a resin paint, pulling the object outof the resin paint, and thus forming a resin layer on the object) isperformed using the first resin material, as shown in (b) of FIG. 6, theresin insulating layer 10 is provided on the inner surface 7 c of thethrough hole 7 and the second surface 2 b of the semiconductor substrate2 (fifth process). Accordingly, in the resin insulating layer 10, arecess 17 having an inner surface that follows the second region 12, thethird region 13, and the fifth region 15 is formed. In addition, thefirst resin material is also adhered to a surface on the side oppositethe semiconductor substrate 2 of the light transmitting substrate 5 anda resin layer 100 is formed. Here, as the first resin material, forexample, a phenolic resin, a polyimide resin, or an epoxy resin can beused.

Subsequently, as shown in (a) of FIG. 7, using a mask (not shown), lightis emitted to only a portion corresponding to a contact hole 16 and aportion corresponding to the opening 10 c in the resin insulating layer10, and only these portions are exposed. Further, light is also emittedto the resin layer 100 (refer to (b) of FIG. 6), and the resin layer 100is also exposed. Then, in the resin insulating layer 10, when theportion corresponding to the contact hole 16, the portion correspondingto the opening 10 c, and the resin layer 100 are developed, the contacthole 16 and the opening 10 c are formed in the resin insulating layer10, and the resin layer 100 (that is, the first resin material adheredto a surface of the light transmitting substrate 5 on the side oppositethe semiconductor substrate 2) is removed. Accordingly, the pad portion3 a of the first wiring 3 is exposed to the opening 10 a of the resininsulating layer 10, and a part of the second surface 2 b of thesemiconductor substrate 2 is exposed to the opening 10 c of the resininsulating layer 10 (sixth process). Here, when the contact hole 16 isformed, an ashing treatment may be performed in combination.

During exposure, a gap is formed due to the recess 17 formed in theresin insulating layer 10 between a light transmitting portion of themask (not shown) and the portion corresponding to the contact hole 16 inthe resin insulating layer 10. Accordingly, light is diffracted andemitted to the resin insulating layer 10. Therefore, during development,the tapered first region 11 that enlarges from the first surface 2 a tothe second surface 2 b of the semiconductor substrate 2 and the contacthole 16 having an inner surface that follows the second region 12 areformed.

Subsequently, as shown in (b) of FIG. 7, for example, when a sputteringmethod using aluminum is performed, the second wiring 8 and the thirdwiring 22 are provided on the surface 10 b of the resin insulating layer10, the first wiring 3 and the second wiring 8 are electricallyconnected in the opening 10 a of the resin insulating layer 10, and thethird wiring 22 and the second surface 2 b of the semiconductorsubstrate 2 are electrically connected in the opening 10 c of the resininsulating layer 10 (seventh process). In this case, since the contacthole 16 has an inner surface following the tapered first region 11 thatenlarges from the first surface 2 a to the second surface 2 b of thesemiconductor substrate 2, a metal film is also reliably formed on theinner surface, and additionally, the first wiring 3 and the secondwiring 8 are reliably connected in the opening 10 a of the resininsulating layer 10.

Subsequently, when a positive-type second resin material having aviscosity of 10 cp or more is prepared and a dip coating method isperformed using the second resin material, as shown in (a) of FIG. 8,the resin protective layer 21 is provided on the surface 10 b of theresin insulating layer 10 to cover the second wiring 8 and the thirdwiring 22 (eighth process). Accordingly, the recess 21 a is formed inthe resin protective layer 21. In addition, the second resin material isalso adhered to a surface of the light transmitting substrate 5 on theside opposite the semiconductor substrate 2 and a resin layer 210 isformed. Here, as the second resin material, for example, a phenolicresin, a polyimide resin, or an epoxy resin can be used.

Subsequently, as shown in (b) of FIG. 8, using a mask (not shown), lightis emitted to only a portion corresponding to the pad portion 8 a of thesecond wiring 8 and a portion corresponding to the pad portion 22 a ofthe third wiring 22 in the resin protective layer 21, and only theseportions are exposed. Further, light is also emitted to the resin layer210 (refer to (a) of FIG. 8), and the resin layer 210 is also exposed.Then, when the portion corresponding to the pad portion 8 a of thesecond wiring 8, the portion corresponding to the pad portion 22 a ofthe third wiring 22, and the resin layer 210 in the resin protectivelayer 21 are developed, the opening 21 b and the opening 21 c are formedin the resin protective layer 21 and the resin layer 210 (that is, thesecond resin material adhered to a surface of the light transmittingsubstrate 5 on the side opposite the semiconductor substrate 2) isremoved. Accordingly, the pad portion 8 a of the second wiring 8 isexposed to the opening 21 b of the resin protective layer 21, and thepad portion 22 a of the third wiring 22 is exposed to the opening 21 cof the resin protective layer 21 (ninth process). Finally, theextraction electrode 9 is arranged in the pad portion 8 a of the secondwiring 8 that is not covered with the resin protective layer 21, theextraction electrode 23 is arranged in the pad portion 22 a of the thirdwiring 22 that is not covered with the resin protective layer 21, andthe semiconductor device 1 described above is obtained.

Processes of the above dip coating method will be described in furtherdetail. In the present embodiment, the first resin material for formingthe resin insulating layer 10 and the second resin material for formingthe resin protective layer 21 are the same. Therefore, the dip coatingmethod for forming the resin insulating layer 10 and the dip coatingmethod for forming the resin protective layer 21 are performed asfollows. Here, the processes of the method of manufacturing thesemiconductor device 1 described above are performed at a wafer level.Finally, a wafer including a plurality of semiconductor devices 1 isdiced and individual semiconductor devices 1 are obtained.

As shown in FIG. 9, a wafer W including portions corresponding to theplurality of semiconductor devices 1 is immersed in a resin material Fstored in a container C. When the wafer W is immersed in the resinmaterial F, a state in which a liquid level FL of the resin material Fstored in the container C intersects the first surface 2 a of thesemiconductor substrate 2 (in the present embodiment, an orthogonalstate, that is, a state in which the first surface 2 a of thesemiconductor substrate 2 is parallel with a vertical direction) ismaintained.

Subsequently, the wafer W including portions corresponding to theplurality of semiconductor devices 1 is pulled out of the resin materialF stored in the container C. When the wafer W is pulled out of the resinmaterial F, a state in which the liquid level FL of the resin material Fstored in the container C intersects the first surface 2 a of thesemiconductor substrate 2 (in the present embodiment, an orthogonalstate, that is, a state in which the first surface 2 a of thesemiconductor substrate 2 is parallel with a vertical direction) ismaintained.

Thereafter, the resin material F applied to the wafer W is pre-baked.When the pre-baking is performed, it is preferable to maintain anorientation of the wafer W as the same orientation when thesemiconductor substrate 2 is immersed in and pulled out of the resinmaterial F. The reason for this is as follows. That is, when thepre-baking is performed, if an orientation of the wafer is changed to anorientation different from the orientation when the semiconductorsubstrate 2 is immersed in and pulled out of the resin material, anadhesion state of the resin material F changes, and there is a risk of aformation state of the resin insulating layer 10 and the resinprotective layer 21 for each through hole 7 changing.

Here, a detailed example of a process of patterning the resin insulatinglayer 10 and the resin protective layer 21 is as follows. That is, aresin material is applied by the dip coating method, the abovepre-baking of the resin material is performed, the above exposure of theresin material is performed, the resin material is baked, the abovedevelopment of the resin material is performed, and the resin materialis baked. Here, baking after the above exposure of the resin material isperformed and baking before the resin material is developed may not beperformed.

As described above, in the method of manufacturing the semiconductordevice 1, processes after the process of thinning the semiconductorsubstrate 2 are performed while the light transmitting substrate 5 isattached to the semiconductor substrate 2. Accordingly, it is possibleto prevent damage to a peripheral portion of the through hole 7. Inaddition, when the dip coating method is performed, the resin insulatinglayer 10 is formed. Accordingly, it is possible to reliably form theresin insulating layer 10 having a sufficient thickness at whichelectrical insulation can be ensured. Therefore, according to the methodof manufacturing the semiconductor device 1, it is possible to preventdamage to a peripheral portion of the through hole 7 while thinning thesemiconductor substrate 2, and it is possible to ensure electricalinsulation between a wiring in the through hole 7 and the semiconductorsubstrate 2.

In the method of manufacturing the semiconductor device 1, in the dipcoating method for forming the resin insulating layer 10 and the dipcoating method for forming the resin protective layer 21, immersion inand pulling out of the resin material F are performed as follows. Thatis, the semiconductor substrate 2 to which the light transmittingsubstrate 5 is attached is immersed in the stored resin material F sothat the liquid level FL of the stored resin material F intersects thefirst surface 2 a of the semiconductor substrate 2, and thesemiconductor substrate 2 to which the light transmitting substrate 5 isattached is pulled out of the stored resin material F so that the liquidlevel FL of the stored resin material F intersects the first surface 2 aof the semiconductor substrate 2. Accordingly, for example, compared towhen immersion in and pulling out of the resin material F are performedwhile the liquid level FL of the stored resin material F and the firstsurface 2 a of the semiconductor substrate 2 are parallel to each other,it is possible to reduce stress generated in the peripheral portion ofthe through hole 7. In addition, for example, compared to when immersionin and pulling out of the resin material F are performed while theliquid level FL of the stored resin material F and the first surface 2 aof the semiconductor substrate 2 are parallel to each other, it ispossible to prevent bubbles from remaining on the resin insulating layer10 formed on the inner surface 7 c of the through hole 7.

In the method of manufacturing the semiconductor device 1, in the dipcoating method for forming the resin insulating layer 10 and the dipcoating method for forming the resin protective layer 21, the same resinmaterial having a viscosity of 10 cp or more is used. When a resinmaterial having a viscosity of 10 cp or more is used, it is possible toreliably form the resin insulating layer 10 having a sufficientthickness at which electrical insulation can be ensured and it ispossible to reliably form the resin protective layer 21 having asufficient thickness at which the second wiring 8 and the third wiring22 can be protected. In addition, since the same resin material is used,even if the resin insulating layer 10 and the resin protective layer 21are deformed due to a change in temperature, the degrees of deformationthereof are the same. Therefore, it is possible to prevent damage to thesecond wiring 8 and the third wiring 222 caused by a large differencebetween the degrees of deformation thereof.

Here, in the dip coating method, a low viscosity resin material (forexample, a resin material used for a water repellent coating, forexample, a resin material having a viscosity of 1 cp or less) isgenerally used. However, even if the dip coating method is performedusing such a resin material, the resin insulating layer 10 is formedwith substantially a uniform thickness along the inner surface 7 c ofthe through hole 7. Thus, in the method of manufacturing thesemiconductor device 1, when the dip coating method is performed using aresin material having a viscosity of 10 cp or more, it is possible toobtain the resin insulating layer 10 having the shape described aboveeasily and reliably.

In the method of manufacturing the semiconductor device 1, when thecontact hole 16 and the opening 10 c are formed in the resin insulatinglayer 10, the resin layer 100 (that is, the first resin material adheredto a surface of the light transmitting substrate 5 on the side oppositethe semiconductor substrate 2) is removed. In addition, when the opening21 b and the opening 21 c are formed in the resin protective layer 21,the resin layer 210 (that is, the second resin material adhered to asurface of the light transmitting substrate 5 on the side opposite thesemiconductor substrate 2) is removed. Therefore, even if the lighttransmitting substrate 5 is used as a support substrate, since the resinlayer 100 and the resin layer 210 are removed from the supportsubstrate, the support substrate can effectively function as the lighttransmitting substrate 5.

Here, it is suitable to remove the resin layer 100 and the resin layer210 separately during each development rather than removing the resinlayer 100 and the resin layer 210 together. When the resin material isadditionally baked after development, since the resin material cannot beremoved after the baking, for example, even if the resin layer 210 andthe resin layer 100 are removed in the last process, when the resinlayer 100 is left, the resin layer 100 cannot be removed. Thus, theresin layer 100 and the resin layer 210 are removed during eachdevelopment. Of course, complete removal of the resin layer 100 and theresin layer 210 is effective when the support substrate is used as thelight transmitting substrate 5. In addition, even if the supportsubstrate is not used as the light transmitting substrate 5 (whenfinally removed), when the resin layer 100 and the resin layer 210 arenot completely removed, an unevenness occurs in a fixed surface in awafer process, the process becomes unstable, and stress is applied tothe semiconductor substrate 2. Therefore, complete removal of the resinlayer 100 and the resin layer 210 is also effective when the supportsubstrate is not used as the light transmitting substrate 5 (whenfinally removed).

In the method of manufacturing the semiconductor device 1, when the dipcoating method is performed, the resin protective layer 21 is formed onthe surface 10 b of the resin insulating layer 10 to cover the secondwiring 8 and the third wiring 22. Accordingly, the shallow recess 21 ahaving a smooth inner surface is formed in the portion corresponding tothe through hole 7 in the resin protective layer 21. Therefore, when thesemiconductor device 1 is mounted in the circuit substrate through theextraction electrode 9 and the extraction electrode 23, and an underfillresin is filled between the semiconductor device 1 and the circuitsubstrate, the underfill resin easily flows inside the recess 21 a, andit is difficult for bubbles and the like to remain inside the recess 21a.

In the method of manufacturing the semiconductor device 1, using thepositive resin material, the resin insulating layer 10 is provided onthe inner surface 7 c of the through hole 7 and the second surface 2 bof the semiconductor substrate 2. Then, when the portion correspondingto the contact hole 16 in the resin insulating layer 10 is exposed anddeveloped, the contact hole 16 is formed in the resin insulating layer10. Accordingly, it is possible to obtain the resin insulating layer 10having the shape described above easily and reliably. Here, duringexposure and development, since the thickness of the portioncorresponding to the contact hole 16 in the resin insulating layer 10becomes thinner (that is, since the portion corresponding to the contacthole 16 is a portion having a height H of ½ of a sum D of the thicknessof the semiconductor substrate 2 and the average thickness of the resininsulating layer 10 provided on the second surface 2 b or less withinthe resin insulating layer 10) due to the recess 17 formed in the resininsulating layer 10, it is possible to obtain the contact hole 16 havinga desired shape easily and reliably.

While one embodiment of the present invention has been described above,the present invention is not limited to the above embodiment. Forexample, while the first opening 7 a of the through hole 7 is coveredwith the pad portion 3 a of the first wiring 3 in the above embodiment,a portion of the first wiring 3 may be located above the first opening 7a, and the first wiring 3 may not cover the entire region of the firstopening 7 a.

In addition, in the above embodiment, the average inclination angle ofthe first region 11 is closer to the average inclination angle of theinner surface 7 c of the through hole 7 than the average inclinationangle of the second region 12. However, the average inclination angle ofthe second region 12 may be closer to the average inclination angle ofthe inner surface 7 c of the through hole 7 than the average inclinationangle of the first region 11.

In addition, in the above embodiment, the light transmitting substrate 5is used as the support substrate. However, when the semiconductor device1 does not include the light transmitting substrate 5, another substratecan be used as the support substrate. When another substrate is used asthe support substrate, after the extraction electrode 9 and theextraction electrode 23 are provided in a process of manufacturing thesemiconductor device 1, the support substrate may be removed from thesemiconductor substrate 2. In addition, when another substrate is usedas the support substrate, the dip coating method is performed, and thusthe resin layer 100 and the resin layer 210 adhered to the supportsubstrate may be removed or left. Further, when another substrate isused as the support substrate, there is no need to use an opticaladhesive as the adhesive layer 6.

In addition, in the above embodiment, when viewed in a directionparallel to the center line CL of the through hole 7, the pad portion 8a of the second wiring 8 and the extraction electrode 9 are positionedin the vicinity of the outside of the second opening 7 b of the throughhole 7. However, the pad portion 8 a of the second wiring 8 and theextraction electrode 9 that are sufficiently separated from the secondopening 7 b of the through hole 7 may be positioned on a surface on theside opposite the second surface 2 b of the semiconductor substrate 2within the surface 10 b of the resin insulating layer 10. However, whenviewed in a direction parallel to the center line CL of the through hole7, even if the pad portion 8 a of the second wiring 8 and the extractionelectrode 9 are positioned in the vicinity of the outside of the secondopening 7 b of the through hole 7, as shown in FIG. 10, stress generatedwhen the extraction electrode 9 expands due to heat or the like isdispersed in directions of arrows A1, A2, and A3. This is because asidewall (inner surface) of the opening 21 b of the resin protectivelayer 21 in which the extraction electrode 9 is provided is curved. Inaddition, this is because the surface 10 b of the resin insulating layer10 provided on the inner surface 7 c of the through hole 7 and thesurface 10 b of the resin insulating layer 10 provided on the secondsurface 2 b of the semiconductor substrate 2 are smoothly connected.Further, stress applied in the direction of the arrow A3 is applied in adirection of an arrow A4 along the second wiring 8. Thus, even if thepad portion 8 a of the second wiring 8 and the extraction electrode 9are positioned in the vicinity of the outside of the second opening 7 bof the through hole 7, a disconnection of the second wiring 8 in thevicinity of a portion of the second opening 7 b of the through hole 7 isprevented. If stress is applied only in the direction of the arrow A3,there is a risk of the opening 21 b of the resin protective layer 21being pressed and widened and the second wiring 8 being disconnected.

In addition, as shown in FIG. 11, the extraction electrode 9 may bearranged inside the through hole 7 to protrude from the second surface 2b of the semiconductor substrate 2. Even if the extraction electrode 9is arranged inside the through hole 7, since the inner surface 7 c ofthe through hole 7 is a tapered surface that enlarges from the firstsurface 2 a to the second surface 2 b, a metal material such as meltedsolder (a material for forming the extraction electrode 9) easily flowsinto the through hole 7 and it is difficult for bubbles and the like toremain inside the through hole 7. In addition, for example, even if someexternal force is applied to the extraction electrode 9 from the secondopening 7 b side to the first opening 7 a side of the through hole 7,the resin insulating layer 10 (in particular, the third curved portion103 described above) functions as a buffer region. Therefore, it ispossible to reduce stress generated in the extraction electrode 9, andit is possible to reliably maintain an electrical connection between thefirst wiring 3, and the second wiring 8 and the extraction electrode 9.Here, when the extraction electrode 9 is arranged inside the throughhole 7, since there is no need to extract the second wiring 8 to theoutside of the second opening 7 b of the through hole 7, when viewed ina direction parallel to the center line CL of the through hole 7, theouter edge of the second wiring 8 may be positioned inside the secondopening 7 b of the through hole 7. That is, the outer edge of the secondwiring 8 may be positioned on a surface on the side opposite the innersurface 7 c of the through hole 7 within the surface 10 b of the resininsulating layer 10.

In addition, as shown in FIG. 12 and FIG. 13, when viewed in a directionparallel to the center line CL of the through hole 7, the outer edge ofthe second wiring 8 except a portion that extends to the pad portion 8 amay be positioned inside the second opening 7 b of the through hole 7.That is, the outer edge of the second wiring 8 except a portion thatextends to the pad portion 8 a may be positioned on a surface on theside opposite the inner surface 7 c of the through hole 7 within thesurface 10 b of the resin insulating layer 10. In this case, since onlythe portion that extends to the pad portion 8 a within the second wiring8 crosses the second opening 7 b of the through hole 7, it is possibleto prevent a current from leaking between the second wiring 8 and thesemiconductor substrate 2 in a portion of the second opening 7 b of thethrough hole 7 more reliably. In particular, when the shape of thesecond opening 7 b of the through hole 7 is rectangular, the portionthat extends to the pad portion 8 a within the second wiring 8 is formedto cross a side portion other than the rectangular corner portion sothat it is possible to prevent a current from leaking between the secondwiring 8 and the semiconductor substrate 2 in a portion of the secondopening 7 b of the through hole 7 more reliably. Here, in FIG. 13, theresin insulating layer 10 is indicated by a dashed line, and the secondwiring 8 is indicated by an alternate long and two short dashes line.

In addition, as shown in FIG. 14, the inner surface 7 c of the throughhole 7 (when the inner surface 7 c of the through hole 7 is a curvedsurface such as a cylindrical surface, the tangential plane of thecurved surface) may be a surface orthogonal to the first surface 2 a andthe second surface 2 b. In this case, a reliable electrical connectionvia the through hole 7 in the semiconductor substrate 2 can be formed.Here, the aspect ratio of the through hole 7 is 0.2 to 10. As anexample, the depth of the through hole 7 is 40 μm, and the width of thesecond opening 7 b is 30 μm. In this case, the aspect ratio is 1.3.Here, the through hole 7 having a shape such as a cylindrical shape or aquadrangular prism shape is formed by, for example, dry etching.

In the through hole 7 shown in FIG. 14, the average inclination angle βof the second region 12 is smaller than the average inclination angle αof the first region 11, and is also smaller than the average inclinationangle γ (in this case, 90°) of the inner surface 7 c of the through hole7. That is, the second region 12 is a region that has a gentlerinclination than the first region 11 and has a gentler inclination thanthe inner surface 7 c of the through hole 7. In addition, the averageinclination angle α of the first region 11 is closer to the averageinclination angle γ of the inner surface 7 c of the through hole 7 thanthe average inclination angle β of the second region 12. Here, therelationship of the average inclination angle γ of the inner surface 7 cof the through hole 7>the average inclination angle α of the firstregion 11>the average inclination angle β of the second region 12 isestablished. Accordingly, it is possible to prevent a disconnection ofthe second wiring 8 and it is possible to obtain the opening 10 a havinga sufficient area for exposing the pad portion 3 a of the first wiring3. In addition, the surface 10 b of the resin insulating layer 10 is acontinuous surface (a surface in which there is no discontinuous portionsuch as an intersection line (such as a corner or an angulated portion)between a surface and a surface, and the regions 11, 12, 13, 14, and 15are smoothly connected). In addition, in the resin insulating layer 10,when the surface S passing through the edge of the opening 10 a of theresin insulating layer 10 and the edge of the second opening 7 b of thethrough hole 7 is set as a boundary surface, and the portion P1 on theinner surface 7 c side of the through hole 7 with respect to the surfaceS and the portion P2 on the side opposite the inner surface 7 c of thethrough hole 7 with respect to the surface S are focused on, the volumeof the portion P1 is larger than the volume of the portion P2. Inaddition, in the resin insulating layer 10, when attention is paid to aregion on one side of the center line CL in the plane including thecenter line CL of the through hole 7, an area of the triangle T1 islarger than an area of the triangle T2. In addition, in a directionparallel to the first surface 2 a and the second surface 2 b of thesemiconductor substrate 2, an average thickness of the portioncorresponding to the first region 11 within the resin insulating layer10 is greater than an average thickness of the portion corresponding tothe second region 12 within the resin insulating layer 10.

In addition, the first region 11 may be the surface 10 b of a portionhaving a height H of ⅔ of a sum D of the thickness of the semiconductorsubstrate 2 and the average thickness of the resin insulating layer 10provided on the second surface 2 b of the semiconductor substrate 2 orless within the resin insulating layer 10 provided on the inner surface7 c of the through hole 7 (refer to FIG. 14). In this case, on thesurface 10 b of the resin insulating layer 10, the first region 11 andthe second region 12 are smoothly connected, and it is possible toreliably prevent a disconnection of the second wiring 8 at a boundarybetween the first region 11 and the second region 12. Here, duringexposure and development, since the thickness of the portioncorresponding to the contact hole 16 in the resin insulating layer 10becomes thinner (that is, since the portion corresponding to the contacthole 16 is a portion having a height H of ⅔ of a sum D of the thicknessof the semiconductor substrate 2 and the average thickness of the resininsulating layer 10 provided on the second surface 2 b or less withinthe resin insulating layer 10) due to the recess 17 formed in the resininsulating layer 10, it is possible to obtain the contact hole 16 havinga desired shape easily and reliably.

In addition, in the method of manufacturing the semiconductor device 1,when the resin insulating layer 10 is provided on the inner surface 7 cof the through hole 7 and the second surface 2 b of the semiconductorsubstrate 2 using the positive resin material, and the portioncorresponding to the contact hole 16 and the portion corresponding tothe opening 10 c in the resin insulating layer 10 are exposed anddeveloped, the contact hole 16 and the opening 10 c are formed in theresin insulating layer 10. However, the present invention is not limitedthereto. For example, using a negative-type resin material, the resininsulating layer 10 may be provided on the inner surface 7 c of thethrough hole 7 and the second surface 2 b of the semiconductor substrate2. In this case, when a portion other than the portion corresponding tothe contact hole 16 and the portion corresponding to the opening 10 c inthe resin insulating layer 10 is exposed, and the portion correspondingto the contact hole 16 and the portion corresponding to the opening 10 cin the resin insulating layer 10 are developed, the contact hole 16 andthe opening 10 c may be formed in the resin insulating layer 10. Thetapered contact hole 16 that enlarges from the second surface 2 b to thefirst surface 2 a of the semiconductor substrate 2 may be formed simplyby the development according to light attenuation, light diffraction,and the like. However, when a heat treatment or the like is additionallyperformed, it is possible to obtain the tapered contact hole 16 thatenlarges from the first surface 2 a to the second surface 2 b of thesemiconductor substrate 2.

In addition, in the above embodiment, the P-type region 2 c in whichP-type impurities are selectively diffused is provided in apredetermined region on the first surface 2 a side in the semiconductorsubstrate 2 including, for example, N-type silicon. However,conductivity-types may be vice versa. In this case, the extractionelectrode 9 and the extraction electrode 23 function as a cathodeelectrode and an anode electrode, respectively. Further, there is nolimitation to a structure in which, in a first-conductivity-type (one ofthe P-type and the N-type) semiconductor substrate 2, asecond-conductivity-type (the other of the P-type and the N-type) regionis formed, and a structure in which, on a first-conductivity-type (oneof the P-type and the N-type) semiconductor substrate 2, asecond-conductivity type (the other of the P-type and the N-type)semiconductor layer is formed, or a structure in which afirst-conductivity-type (one of the P-type and the N-type) semiconductorlayer is formed on a substrate and a second-conductivity-type (the otherof the P-type and the N-type) semiconductor layer formed on thefirst-conductivity-type semiconductor layer may be used. That is, thesecond-conductivity-type region may be formed on thefirst-conductivity-type region of the semiconductor substrate 2. Inaddition, in the above embodiment, the semiconductor device 1 is anoptical device, for example, a silicon photodiode. However, thesemiconductor device 1 may be another optical device, or may be anelectronic device, or the like.

In addition, in the method of manufacturing the semiconductor device 1,the resin insulating layer 10 and the resin protective layer 21 areprovided by performing the dip coating method. However, the presentinvention is not limited thereto. For example, the resin insulatinglayer 10 and/or the resin protective layer 21 may be provided byperforming another method such as a lamination method using a resinsheet and a spin coating method using a resin paint.

INDUSTRIAL APPLICABILITY

According to the present invention, it is possible to provide a methodof manufacturing a semiconductor device through which it is possible toprevent damage to a peripheral portion of a through hole while thinninga semiconductor substrate, and it is possible to ensure electricalinsulation between a wiring in the through hole and the semiconductorsubstrate.

REFERENCE SIGNS LIST

-   -   1: Semiconductor device, 2: Semiconductor substrate, 2 a: First        surface, 2 b: Second surface, 3: First wiring, 5: Light        transmitting substrate (support substrate), 7: Through hole, 7        a: First opening, 7 b: Second opening, 7 c: Inner surface, 8:        Second wiring, 10: Resin insulating layer, 10 a: Opening, 10 b:        Surface, 16: Contact hole, 21: Resin protective layer.

1. A method of manufacturing a semiconductor device comprising: a firstprocess in which a first wiring is provided on a first surface of asemiconductor substrate including the first surface and a second surfaceopposite to each other; a second process in which a support substrate isattached to the first surface after the first process; a third processin which a portion of the semiconductor substrate on the second surfaceside is removed and thus the semiconductor substrate is thinned so thatthe thickness of the semiconductor substrate is smaller than thethickness of the support substrate after the second process; a fourthprocess in which a through hole to extend from the first surface to thesecond surface is formed in the semiconductor substrate, and a part ofthe first wiring is exposed to a first opening of the through hole onthe first surface side after the third process; a fifth process in whicha dip coating method is performed using a first resin material and thusa resin insulating layer that is continuous through a second opening ofthe through hole on the second surface side is provided on an innersurface of the through hole and the second surface after the fourthprocess; a sixth process in which a contact hole is formed in the resininsulating layer, and the part of the first wiring is exposed to anopening of the contact hole on the first surface side after the fifthprocess; and a seventh process in which a second wiring is provided on asurface of the resin insulating layer, and the first wiring and thesecond wiring are electrically connected in the opening of the contacthole on the first surface side after the sixth process.
 2. The method ofmanufacturing a semiconductor device according to claim 1, wherein, inthe fifth process, the semiconductor substrate to which the supportsubstrate is attached is immersed in the stored first resin material sothat a liquid level of the stored first resin material intersects thefirst surface, and the semiconductor substrate to which the supportsubstrate is attached is pulled out of the stored first resin materialso that the liquid level of the stored first resin material intersectsthe first surface.
 3. The method of manufacturing a semiconductor deviceaccording to claim 1, wherein, in the fifth process, the dip coatingmethod is performed using the first resin material having a viscosity of10 cp or more.
 4. The method of manufacturing a semiconductor deviceaccording to claim 1, wherein, in the sixth process, the first resinmaterial adhered to a surface of the support substrate on the sideopposite the semiconductor substrate in the fifth process is removed. 5.The method of manufacturing a semiconductor device according to claim 1,further comprising an eighth process in which a dip coating method isperformed using a second resin material and thus a resin protectivelayer is provided on a surface of the resin insulating layer to coverthe second wiring after the seventh process, and a ninth process inwhich an opening is formed in the resin protective layer and a part ofthe second wiring is exposed to the opening after the eighth process. 6.The method of manufacturing a semiconductor device according to claim 5,wherein, in the eighth process, the semiconductor substrate to which thesupport substrate is attached is immersed in the stored second resinmaterial so that a liquid level of the stored second resin materialintersects the first surface, and the semiconductor substrate to whichthe support substrate is attached is pulled out of the stored secondresin material so that the liquid level of the stored second resinmaterial intersects the first surface.
 7. The method of manufacturing asemiconductor device according to claim 5, wherein, in the eighthprocess, the dip coating method is performed using the second resinmaterial having a viscosity of 10 cp or more.
 8. The method ofmanufacturing a semiconductor device according to claim 5, wherein, inthe ninth process, the second resin material adhered to a surface of thesupport substrate on the side opposite the semiconductor substrate inthe eighth process is removed.
 9. The method of manufacturing asemiconductor device according to claim 5, wherein the first resinmaterial and the second resin material are the same.